This invention relates to a video signal transmission apparatus for television broadcasting systems, video tape recorders, and others.
Some video cassette recorders (VCR) for broadcasting use or business use are designed to record two-channel component video signals including a luminance signal and a time-base compressed color signal respectively.
U.S. patent application Ser. No. 890,347 filed on July 7, 1986, now U.S. Pat. No. 4,811,119, discloses a VCR in which two-channel component video signals are periodically and mutually changed or switched at given periods of nH ("H" denotes a horizontal sync period; "n" denotes an arbitrary integer) before they are recorded. A similar signal-switching process is performed during the reproduction of recorded signals. When two-channel component video signals reproduced from this VCR are visualized on a television receiver screen, the displaced pictures are susceptible to unwanted phenomena such as flickers and dot crawling since a luminance difference and a time difference of 30 Hz or 25 Hz tends to occur between the same scanning lines of two successive frames.
Japanese Published Unexamined Patent Application 62-29381 discloses an advanced two-channel video signal transmission apparatus for a recording and reproducing system which removes a luminance difference and a time difference of 30 Hz or 25 Hz from the same scanning lines and thus which suppresses flickers and dot crawling in reproduced pictures. In the video signal transmission apparatus of Japanese Application 62-29381, one line is lost for each frame which generally has 525 lines. The lost video information is restored through an interpolation process.